George Carless wrote:
> I feel that, while the most immediately natural response to the opening
> stanza is to see it as an introduction that's setting the scene, there's
> more to it than that.  Although the streets are no doubt literal, I'm not
> sure whether they're literal *in the current moment* of the speaker, as it
> were.

Let us go -- i.e., we haven't gone yet or "we" would say something like,
"Let's keep on trucking, you and I." The streets are literal in the only
sense in which the future tense can be literal, naming something that is
going to be present tense after some interval.

Does "he" ever start out actually following the streets, or is the whole
poem a mental exploration of what might or would happen if he would
follow up on the first line and go. (I'm still assuming that "you" and
"I" are the same person, muttering to himself.

For a "modern" reader, Dante's hell could exist, even for Dante, only in
his head, so the _Inferno_ becomes a dialogue of the self with the self
-- hence the epigraph. Nothing gets out of the inferno of the mind. And
that of course is what Prufrock is complaining to himself about: his
inability to get out of himself.